# Dictionary Definition

joule

### Noun

1 a unit of electrical energy equal to the work
done when a current of one ampere passes through a resistance of
one ohm for one second [syn: J, watt
second]

2 English physicist who established the
mechanical theory of heat and discovered the first law of
thermodynamics (1818-1889) [syn: James
Prescott Joule]

# User Contributed Dictionary

### Pronunciation

- , /dʒul/, /dZul/

### Noun

#### Translations

- Basque: joule
- Bulgarian: джаул (džaul)
- Catalan: joule
- Chinese: 焦耳 (jiāo ěr)
- Croatian: džul
- Czech: joule
- Danish: joule
- Dutch: joule
- Esperanto: ĵulo
- Finnish: joule
- French: joule
- Galician: joule
- German: Joule
- Hebrew: ג׳ול (jul)
- Hungarian: joule
- Indonesian: joule
- Italian: joule
- Japanese: ジュール (jūru)
- Korean: 줄 (jul)
- Latvian: džouls
- Luxembourgish: joule
- Malay: joule
- Norwegian: joule
- Polish: dżul
- Portuguese: joule
- Romanian: joule
- Russian: джоуль (džoul’)
- Serbian: џул
- Slovak: joule
- Slovene: joule
- Spanish: julio
- Swedish: joule
- Thai: (jun)
- Turkish: joule
- Ukrainian: джоуль (džoul’)

## Dutch

### Noun

joule## Finnish

### Noun

joule## French

### Noun

joule## Italian

### Noun

joule# Extensive Definition

The joule ( or /ˈdʒaʊl/) (symbol: J) is the SI unit of
energy measuring heat,
electricity and
mechanical
work. It was named after English physicist James
Prescott Joule.

## Description

One joule is the work done, or energy expended, by a force of one newton moving one metre along the direction of the force. This quantity is also denoted as a newton metre with the symbol N·m. Note that torque also has the same units as work, but the quantities are not the same. In elementary units:- \, 1\, \mathrm=1\, \mathrm \cdot \mathrm

- \, 1\, \mathrm=1\, \mathrm \cdot \frac

One joule is also:

- The work required to move an electric charge of one coulomb through an electrical potential difference of one volt; or one coulomb volt, with the symbol C·V.
- The work done to produce power of one watt continuously for one second; or one watt second (compare kilowatt hour), with the symbol W·s. Thus a kilowatt hour is 3,600,000 joules or 3.6 megajoules

## History

A joule is the mechanical equivalent of heat
meaning the number of units of work in which the unit of heat can
perform. Its value was found by James
Prescott Joule in experiments that showed the mechanical energy
Joule's equivalent, and represented by the symbol J. The term was
first introduced by Dr. Mayer of Heilbronn.

## Conversions

1 joule is exactly 107 ergs.1 joule is approximately equal to:

- 6.2415 eV (electronvolts)
- 0.2390 cal (calorie) (small calories, lower case c)
- 2.3901 kilocalorie, Calories (food energy, upper case C)
- 9.4782 BTU (British thermal unit)
- 0.7376 ft·lbf (foot-pound force)
- 23.7 ft·pdl (foot poundals)
- 2.7778 kilowatt hour
- 2.7778 watt hour
- 9.8692 litre-atmosphere

1 joule in everyday life is approximately:

- the energy required to lift a small apple one metre straight up.
- the energy released when that same apple falls one meter to the ground.
- the amount of energy, as heat, that a quiet person generates every hundredth of a second.
- the energy required to heat one gram of dry, cool air by 1 degree Celsius.
- one hundredth of the energy a person can get by drinking a single drop of beer.
- the kinetic energy of an adult human moving a distance of about a handspan every second.

Units defined in terms of the joule include:

- 1 thermochemical calorie = 4.184 J
- 1 International Table calorie = 4.1868 J
- 1 watt hour = 3600 J
- 1 kilowatt hour = 3.6 J (or 3.6 MJ)
- 1 ton TNT = 4.184 GJ

Useful to remember:

- 1 joule = 1 newton metre = 1 watt second

### SI multiples

## See also

## References

- The adoption of joules as units of energy, FAO/WHO Ad Hoc Committee of Experts on Energy and Protein, 1971. A report on the changeover from calories to joules in nutrition.

## External links

joule in Afrikaans: Joule

joule in Arabic: جول

joule in Asturian: Xuliu (unidá)

joule in Bengali: জুল

joule in Belarusian: Джоўль

joule in Belarusian (Tarashkevitsa):
Джоўль

joule in Bosnian: Džul

joule in Bulgarian: Джаул

joule in Catalan: Joule

joule in Czech: Joule

joule in Danish: Joule

joule in German: Joule

joule in Estonian: Džaul

joule in Modern Greek (1453-): Τζάουλ (μονάδα
μέτρησης)

joule in Spanish: Julio (unidad)

joule in Esperanto: Ĵulo

joule in Basque: Joule (unitatea)

joule in Persian: ژول

joule in French: Joule

joule in Scottish Gaelic: Joule

joule in Galician: Joule (unidade)

joule in Korean: 줄 (단위)

joule in Croatian: Džul

joule in Indonesian: Joule

joule in Icelandic: Júl

joule in Italian: Joule

joule in Hebrew: ג'ול

joule in Swahili (macrolanguage): Jouli

joule in Latin: Joulium

joule in Latvian: Džouls

joule in Lithuanian: Džaulis

joule in Hungarian: Joule

joule in Malay (macrolanguage): Joule

joule in Dutch: Joule

joule in Japanese: ジュール

joule in Norwegian: Joule

joule in Norwegian Nynorsk: Joule

joule in Occitan (post 1500): Joule

joule in Polish: Dżul

joule in Portuguese: Joule

joule in Kölsch: Joule (Mohß)

joule in Romanian: Joule

joule in Russian: Джоуль

joule in Simple English: Joule

joule in Slovak: Joule

joule in Slovenian: Džul

joule in Serbian: Џул

joule in Finnish: Joule

joule in Swedish: Joule

joule in Thai: จูล

joule in Vietnamese: Joule

joule in Turkish: Joule (birim)

joule in Ukrainian: Джоуль

joule in Urdu: جاؤل

joule in Venetian: Joule

joule in Chinese: 焦耳